Police in Tokyo have arrested a female employee at a pub in Shinjuku's Kabukicho district on suspicion of forcing a female customer into prostitution to pay off an outstanding debt.

Police officers say 23-year-old Katsumata Yuna slapped a customer of the same age in the face and threatened her in December of last year.

They say Katsumata worked at the pub. She dressed as a man and tended female customers who were looking for male companions.

She allegedly made the victim order expensive champagne and charged her 3 million yen, or more than 20,000 dollars, a night.

Sources say Katsumata told the woman to make money by prostituting herself. She reportedly forced the woman to become a streetwalker in the Kabukicho district and sent her to sex shops across the country. The woman is said to have been forced to sell herself for about six months.

The suspect allegedly pocketed almost all of the 3.5 million yen, or about 23,500 dollars, that the woman earned.

Katsumata has reportedly denied the charge that she assaulted the woman, but she has admitted that she urged the woman to transfer the money.

Attempts to recover money that is owed often lead to trouble between customers and male host clubs or other nightlife establishments in Kabukicho.

In many cases, women who are unable to pay up are forced into prostitution. The police have been cracking down on the practice.